Hi there!
You can check here http://doc.uvlayout.com/User_Guide:_About_UVLayout
Load Settings > MaxShells
When an OBJ file is loaded in Edit mode, the number of UV shells is checked first; if there’s more than this setting, the load is aborted and a message is displayed suggesting that the Weld UVs load option might be needed. If your mesh really does have more than the default of 2000 shells (e.g. individual leaves on a tree) then you can increase the shell limit here.
So try to open UVLayout and enter there MaxShells 100000 or more, or try to delete UVmap before sending.